1. FIELD OF THE INVENTION
The present invention generally relates to a safety shield and more specifically a shield to be used while arming and handling oilfield and other explosive devices. The shield is constructed of anti-shrapnel materials and is of tubular construction to directionally concentrate and channelize explosive forces away from workers during the assembly, arming and handling of explosive devices of various types and especially wireline explosive devices utilized in oilfields such as wireline guns, jet cutters, chemical cutters and perforating charges with the shield containing and diverting the directionally concentrated shaped charges away from personnel operating the device.
2. INFORMATION DISCLOSURE STATEMENT
Numerous devices are used in the oilfield to penetrate tubular metal pipes oriented in a vertical well bore. Such devices have high energy output and are usually explosive devices that are detonated with blasting caps or small explosive shells. An inherent hazard exists when handling, assembling, arming or running these devices into the work area due to the close association of blasting caps or explosive shells with the penetrating medium and instances of severe injury and fatal accidents have occurred since devices capable of penetrating metal tubular pipes or other tubular members are capable of producing shrapnel that can seriously injure and even fatally injure adjacent personnel. One example of this ongoing problem is in the production of oil in which the well bore includes a casing and tubing inside the casing. The tubing must be perforated at selected depths which is usually accomplished by the use of an explosive device detonated from the surface by an electrical charge which is transmitted through a device known as a "wireline". It is also necessary to rework a well at certain times which requires the cutting and retrieving of the tubing with the tubing usually being cut with an explosive device known as a "jet cutter" or "tubing cutter" which is also detonated through a wireline from the surface. There have been instances where the explosive devices have been detonated prematurely by stray voltage charges, radio charges and human error which can result in serious bodily injury or death to adjacent personnel.
The following U.S. patents are relevant to the invention but they do not disclose a structure equivalent to the invention.
2,417,331 PA1 3,721,201 PA1 4,027,601 PA1 4,531,639 PA1 4,723,800 PA1 4,733,773